Pumps



United States Patent 3,269,323 PUMPS Kenneth R. Lung, Morehead City,N.C., assignor to The Tait Manufacturing Company, Dayton, Ohio, acorporation of Ohio Filed Dec. 30, 1964, Ser. No. 422,371 6 Claims. (Cl.103-87) This invention relates to submersible pumps, and moreparticularly to a multi-stage submersible motor-pump assembly having animproved arrangement of the housing and impellers whereby the impellersare maintained in axial alignment without the need for a pump shaft.

Primarily, the apparatus of the present invention is directed to asubmersible pump assembly which is intended for submerging into a well,within the well casing, and which operates in response to the pressurevariances within a supply tank connected by a pipe line with the pump.The invention has particular reference to an improved motor-pumpassembly which provides for economical construction and, in addition,may be easily assembled for economical production and easilydisassembled for servicing.

Accordingly, it is a primary object of the present invention to providea multi-stage submersible pump assembly having an improved impeller andhousing structure which makes possible an aligned assembly of theimpellers to the motor without requiring a pump shaft.

As another object, the present invention provides a submersiblemulti-stage pump having a plurality of impellers and a novelconstruction for interlocking successive impellers together for drivingengagement in such manner as to maintain axial alignment therebetweenwhile providing for relative axial movement between adjacent impellersto permit the upward end thrust developed by each impeller to beabsorbed within its corresponding housing.

Still another object of the present invention is to provide asubmersible pump as outlined above which has an improved constructionfor connecting the impellers to the motor shaft in order that themotor-pump assembly may be easily assembled for economical productionand disassembled for servicing.

A further object of the invention is to provide a submersible pump asoutlined above wherein a series of impellers are adapted to drive eachother in a successive manner and to distribute equally the drive loadaround the periphery of the impeller hub so that the impellers may beconstructed inexpensively from a plastic material which resistscorrosion and provides a smooth unfinished surface for high pumpefficiency.

Other objects and advantages will be apparent from the followingdescription, the accompanying drawing and the appended claims.

In the drawing:

FIG. 1 is an elevational view illustrating a submersible pump assemblyincorporating the improved impeller structure and positive drivearrangement between successive impellers and the motor shaft inaccordance with the present invention;

FIG. 2 is an enlarged detail view in axial section of the motor portionof the motor-pump assembly shown in FIG. 1;

FIG. 3 is an enlarged fragmentary view in axial section through the pumpportion of the motor-pump assembly of FIG. 1 showing details ofconstruction in accordance with a preferred embodiment of the invention;and

FIG. 4 is an enlarged section on the line 44 of FIG. 3.

Referring to the drawing, which illustrates a preferred embodiment ofthe present invention, the submersible pump assembly includes a pump 12of the mu-lti-stage centrifugal type and a motor 14 having electricleads 15 which are protected by the shield 16. The lower end of the pump12 includes an intake housing 18 which serves to connect the pumprigidly to the motor 14. A cylindrically shaped perforated screen 19 ismounted around'the intake housing 18 and serves to filter the liquidflowing into the pump 12.

As shown in the enlarged detail view of FIG. 2, the motor 14 generallyincludes a motor shaft 20 and rotor 22 which are rotatably mountedwithin the sleeve type bearings 24 fitted within the end brackets 26 and27. The motor casing 30 serves to support the end brackets 26 and 27 andalso the stator 31, which is mounted within the cylindrically shapedyoke 33. Thrust washers are provided on each end of the rotor 22 and areadapted to rotate with the motor shaft 20 against the end of the sleevebearings 24 in order to oppose the axial thrust which is transferred tothe motor shaft 20 from the pump '12. It is to be understood, however,that other suitable bearing means, as for example, ball bearings, can beused to take both the radial and axial thrust produced on the motorshaft.

Referring to FIG. 3, the bottom of the intake housing 18 includes anannular mounting flange 40 which is secured rigidly to the end bracket27 of the motor 14 by a series of cap screws 42. The upper end of theintake housing 18 includes a male threaded portion 43 which extendsupwardly from the top plate 45. Integrally connecting the top plate 45to the mounting flange 4%) are a series of four radially spaced ribs 47which support the bearing retaining hub 49.

Connected to the-threaded portion '43 and extending upwardly from thetop of the intake housing 1 8 are the stacked pump housing 50 and topsupport housing 5.1 which are preferably formed from a non-corrosiveplastic material and have threaded connections '52 for removablycoupling the housings together to delflne the separate stages of thepump. While only three stages are shown, it is to be understood that anynumber of stages can be employed depending upon the output pressure andflow rate desired. As shown, the top support housing 5'1 is providedwith a series of suitable vanes 53 which serve to support the topsupport plate 54. Rigidly mounted within each of the pump housings 50 isa diffuser member 57 which cooperates with the top plate 59 of each pumphousing 50 to direct a smooth [flow of liquidradially inwardly to theinlet portion of an impeller 60.

Each of the impellers 60 includes a top opening having an internalspline 61 formed therein which is adapted to receive slidably anexternal spline formed on the lower hub extension '62 of the aboveadjacent impeller to form a socket connection which provides both axialand radial alignment of the impellers. The lower hub extension 62 of thebottom impeller is similarly connected with a splined socket in theupper end portion of a coupling 65 which is attached by a splineconnected 67 to the motor shaft 20 for positive driving thereby.

Surrounding the lowermost hub extension 62 and retained by the hub 4-9is a bearing sleeve 72 preferably formed from a material having a lowcoeflicient of friction, as for example, a plastic such as a fluorinatedhydrocarbon or similar material. Each of the hub extensions 62 of theimpellers 60 includes a cylindrical portion 73 which is rotatablysupported in a cylindrical bearing surface provided by a flange 74formed as a part of the associated diffuser member 57. These bearings 72and 74 cooperate with the spline connection between the impellers 60 tohold the impellers in axial alignment with the motor shaft 20.

The downward axial thrust produced by the impellers 60 of the pumpduring operation is transferred to the motor shaft 20 and is opposed bythe thrust washers 35 (FIG. 2) spaced on the opposite ends of the rotor22. In some installations, however, the impellers 60 may produce anupward thrust. When this happens, the upward thrust produced by eachimpeller is carried by each corresponding stage housing by the thrustbearing or washer 80 spaced between the top surface of each impeller 60and the bottom surface of the flange 74 formed as part of the diffusermember 57. The upward thrust produced by the top impeller 60 is carriedby support plate 54 forming a part of the top housing 51 and providedwith a central projection '81 which spaces the top thrust washer 80.Thus as a result of the axially floating spline connection between eachimpeller 60, the impellers are adapted to move relative to one anotherto distribute the combined upward thrust uniformly over the housings 50and 51. Furthermore, it can be seen that the axial spacing of thehousings and impellers is not critical as a result of the axial floatingprovided for each impeller while maintaining the axial alignment.

One important feature which is provided by the successively connectedimpellers is the substantial cost of saving which results fromeliminating the pump shaft. Commonly, the pump shaft is constructed froma corrosion resistant material such as stainless steel and thus addssignificant cost to the pump portion of the submersible motor-pumpassembly. On the other hand, the impellers formed in accordance with thepresent invention may be molded from a plastic material which offerscorrosion resistance in addition to considerable cost savings.[Furthermore, the molded plastic impellers substantially eliminate theneed for machining the impellers after the molding operation. Inaddition, the coupling 65 may be formed from a suitable plastic bearingmaterial, in which case, all of the rotary components of the pump areformed of a corrosion resistant plastic material.

Another desirable feature which is provided by a pump formed accordingto the invention is the simple and convenient manner in which the pumpcan be assembled and disassembled. For example, by simply unthreadingthe housings 50, the pump may be separated at any stage for servicing orreplacement without disturbing the next adjacent stage. For example, theupper housing 51 and enclosed impeller 60 may be removed withoutdisturbing the adjacent pump stage housing 50 and its enclosed impeller60. On the other hand, if it is desirable to remove only the motor 14from the pump 12, the motor may be separated by simply removing thescreen 19 and the screws 42, since the motor shaft 20 can slide out ofengagement with the coupling 65.

It is to be understood that the term spline connection as used herein isintended to include any aligned socket arrangement whereby the loadingtransferred through the connection is distributed generally uniformlyaround the periphery of the hub extensions '62 and also provides forrelative axial movement between adjacent impellers while maintainingaxial and radial alignment of the impellers in the housings.

While the form of apparatus herein described constitutes a preferredembodiment of the invention, it is to be understood that the inventionis not limited to this precise form of apparatus, and that changes maybe made therein without departing from the scope of the invention whichis defined in the appended claims.

What is claimed is:

1. An improved submersible multi-sta-ge pump adapted to be driven by adrive shaft extending from a motor, comprising a plurality of pumphousings connected rigidly together in stacked relationship, acorresponding plurality of impellers arranged With one impellerpositioned in each said housing, integral hub extension means projectingaxially from one side of each of said impellers and having externalspline means formed thereon, means defining an axial opening in theopposite side of each said impeller having corresponding internal splinemeans for receiving said hub extension means of the adjacent saidimpeller to form a positive drive socket connection therebetween and formaintaining said impellers in radial and axial alignment, meansseparably connecting adjacent said pump housings and correspondingimpellers to provide for convenient servicing of the pump, and couplingmeans for connecting the end impeller to the motor drive shaft forrotating said impellers by transferring the torque successively fromo'nesaid impeller to the adjacent said impeller through said socketconnections.

2. An improved submersible multi-stage pump adapted to be driven by adrive shaft extending from a motor, comprising a plurality of pumphousings connected rigidly together in stacked relationship, acorresponding plurality of impellers arranged with one impellerpositioned in each said housing, integral hub extension means projectingaxially from each of said impellers and having external spline meansformed thereon, means defining an axial opening in each said impellershaving corre sponding internal spline means for receiving said hubextension means of the adjacent said impeller to form a positive drivesocket connection there'between and to provide for relative axialmovement between adjacent said impellers while maintaining saidimpellers in radial and axial alignment, bearing means associated witheach stage housing for opposing axial thrust produced by said impellerspaced Within, means for separably connecting adjacent said pumphousings and corresponding impellers to provide for convenient servicingof the pump stages, and coupling means for connecting the end impellerto the motor drive shaft for rotating said impellers by transferring thetorque successively from one said impeller to the adjacent said impellerthrough said socket connections.

3. An improved submersible motor-pump combination comprising a motorhaving a submersible casing and including an upwardly projecting motorshaft, a plurality of stage pump housings connected rigidly together instacked relationship and connected to the top end of said motor casing,a corresponding plurality of impellers arranged with one impellerpositioned in each said housing, coupling means for connecting saidmotor shaft to the bottom said impeller and adapted to provide axial.alignment therebetween, said impellers each having a hub extension onone side and means defining a central opening on the opposite side,corresponding spline means formed on said hub extension and in saidopening for providing driving engagement between adjacent said impellersand to maintain axial alignment therebetween while providing forrelative axial movement between adjacent said impellers, and bearingmeans associated with each stage housing for opposing axial thrustdeveloped by said impeller spaced within.

4. An improved submersible motor-pump combination comprising a motorhaving a submersible casing and including a projecting motor shafthaving an external spline formed thereon, pump housing means connectedrigidly to one end of said motor casing and including a plurality ofseparable stage housings, a plurality of impellers spaced in stackedrelationship within said housings and adapted to increase progressivelythe pressure of the liquid passing through said housing means, acoupling having an internal spline for providing a driving connection tosaid motor shaft and adapted to drive the adjacent said impeller and toprovide axial alignment therebetween, said impellers each having anintegral hub extension on one side and mean-s defining an opening on theopposite side to provide for a socket driving connection between the hubextension of one impeller and said opening formed within an adjacentimpeller to maintain axial alignment therebetween and to provide forrelative sliding movement, a cylindrical surface formed on said hubextension, bearing means carried by each said stage housings andengaging said cylindrical surface for rotatably supporting saidimpellers, and means on each said stage housings for opposing axialthrust developed by said corresponding impeller.

5. An improved submersible motor-pump combination comprising a motorhaving a submersible casing and including a projecting motor shaft, amulti-stage pump housing connected rigidly to one end of said motorcasing, a plurality of impellers spaced in stacked relationship withinsaid housing, coupling means forming a splined driving connectionbetween said motor shaft and the adjacent said impeller, an integral hubextension projecting axially from each of said impellers having anexternal spline formed thereon, means defining an opening in each ofsaid impellers and having a spline formed thereon to provide a drivingconnection between said impeller and said hub extension of the adjacentsaid impeller and cooperating with said hub extension to maintainadjacent said impellers in radial and axial alignment within saidhousing, bearing means can'ied by said housing for rotatably supportingthe hub extension of said impellers, bearing means within said motor foropposing axial thrust transferred downwardly to said motor shaft fromsaid impellers, and thrust bearing means within said housing to opposethe upward axial thrust developed by said impellers.

6. An improved submersible motor-pump combination comprising a motorhaving a submersible casing and including a projecting motor shaft, amulti-stage pump housing connected rigidly to the top end of said motorcasing, a plurality of impellers positioned in stacked relationshipwithin said housing, coupling means forming a driving connection betweensaid motor shaft and the adjacent said impeller, an integral hubextension projecting axially from each of said impellers and having anexternal spline formed thereon, means defining an opening in each ofsaid impellers having a spline formed therein to provide a drivingconnection between said impeller and said hub extension of the adjacentsaid impeller and cooperating with said hub extension to maintainadjacent said impellers in radial and axial alignment within saidhousing, a cylindrical bearing surface formed on each of said hubextensions, bearing means carried by said housing for rotatablysupporting said bearing surface on said hub extensions of saidimpellers, thread means separably connecting adjacent said pump housingsfor axial separation of said impellers to provide for convenientservicing of the pump stages, bearing means within said motor foropposing axial thrust transferred downwardly to said motor shaft fromsaid impellers, and thrust bearing means within said housing to opposethe upward axial thrust developed by said impellers.

References Cited by the Examiner UNITED STATES PATENTS 3,076,411 2/1963Guillory 103-102 3,154,019 10/1964 Hoyt 103-87 3,188,967 6/ 1965Glessner 103-408 ROBERT M. WALKER, Primary Examiner.

1. AN IMPROVED SUBMERSIBLE MULTI-STAGE PUMP ADAPTED TO BE DRIVEN BY ADRIVE SHAFT EXTENDING FROM A MOTOR, COMPRISING A PLURALITY OF PUMPHOUSINGS CONNECTED RIGIDLY TOGETHER IN STACKED RELATIONSHIP, ACORRESPONDING PLURALITY OF IMPELLERS ARRANGED WITH ONE IMPELLERPOSITIONED IN EACH SAID HOUSING, INTEGRAL HUB EXTENSION MEANS PROJECTINGAXIALLY FROM ONE SIDE OF EACH OF SAID IMPELLERS AND HAVING EXTERNALSPLINE MEANS FROMED THEREON, MEANS DEFINING AN AXIAL OPENING IN THEOPPOSITE SIDE OF EACH SAID IMPELLER HAVING CORRESPONDING INTERNAL SPLINEMEANS FOR RECEIVING SAID HUB EXTENSION MEANS OF THE ADJACENT SAIDIMPELLER TO FORM A POSITIVE DRIVE SOCKET CONNECTION THEREBETWEEN AND FORMAINTAINING SAID IMPELLERS IN RADIAL AND AXIAL ALIGNMENT, MEANSSEPARABLY CONNECTING ADJACENT SAID PUMP HOUSINGS AND CORRESPONDINGIMPELLERS TO PROVIDE FOR CONVENIENT SERVICING OF THE PUMP, AND COUPLINGMEANS FOR CONNECTING THE END IMPELLER TO THE MOTOR DRIVE SHAFT FORROTATING SAID IMPELLERS BY TRANSFERING THE TORQUE SUCESSIVELY FROM ONESAID IMPELLER TO THE ADJACENT SAID IMPELLER THROUGH SAID SOCKETCONNECTIONS.